Hydraulic propeller



(M odel.)

H. MULHOLLEN'.

HYDRAULIC PROPELLER. "No. 241-679. Patented Sept. 27,1881.

UNITED STATES PATENT OFFICE.

HUGH MULHOLLEN, OF FOSTORIA, PENNSYLVANIA.

HYDRAULIC PROPELLER.

SPECIFICATION forming part of Letters Patent No. 247,679, datedSeptember 27, 1881. Application filed August 16, 1881. (Model.)

To all whom it may concern:

Be it known that I, HUGH MULHOLLEN, of Fostoria, in the county of Blair,and in the State of, Pennsylvania, have invented certain new and usefulImprovements in Propellers for Vessels; and I do hereby declare that thefollowing is a full,clear, and exactdescription thereof, reference beinghad to the accompanying drawings, and to the letters of reference markedthereon, making a part of this specification. Y v

This invention relates to propellers for boats wherein pistonsreciprocate inside of cylinders which are submerged, and which may bearranged at the stern, at the sides, or at the bow of a boat.

The nature of my invention and improvement consists, mainly, inprovidingeach pistoncylinder with a side outlet for water, incombination with cylindrical valves acted on by springs and arrangedback of the pistons, said valvesbeing intended for closing the sideoutlets at certain times, and allowing the escape of any water which mayleak into the cylinders back of the pistons. I also employ air-tubes forthe cylinders, so arranged as to allow the free escape of air, as willbe hereinafter explained.

In order to enable others skilled in the art to which my inventionappertains to make and use the same, I will proceed to describe itsconstruction and operation, referring to the annexed drawings, in which-Figure 1 is .a plan view of two propellers, their piston-rods,crank-shat t, and pitman-rod; Fig. 2, a longitudinal section takenvertically through one of the propellers. Fig. dis a section takenvertically and transversely through the cylinders in the plane indicatedby the dotted line :10 w on Fig.

The letters A A designate two cylinders,- which are constructed withclosed heads a a, and with side outlets, b 11, leading into chutes B B,that extend to the open ends of the cylinders outside thereof.

The outlets b b are located near the closed heads of the cylinders, andin or nearly in the same vertical plane with these water-outlets aretubular outlets B, which allow a free escape of air from the cylinders Aback of the pistons, and which should be of such length as to extendwell. above. the highest waterlevel. V

The two cylinders A A are suitably mounted either at the stern of a boator at any other desired point thereof. Inside of each cylinder A is apiston, O, which is suitably packed, and which is provided with apiston-rod, D, that passes through a stuffing-box applied to the head a.The piston -rods are connected by jointed rods E to a crank-shaft, F,which receives rotation from any convenient prime motor.

It is not intended that the pistons shall be packed so tightly in theircylinders as shall exclude the possibility of water getting between them(the pistons) and the cylinderheads, especially when the boat isstationary for some time. I get rid of this water which is between thepiston-heads and pistons by the following contrivance:

D D designate two cylindrical valves or flanged heads, arranged betweenthe pistons and cylinder-heads and packed loosely in the cylinders. Thepiston rods D play freely through the valves D, and these valves areconnected to the cylinder-heads by means of springs F. (Shown in Fig.2.) The valves are held by the springs F, so as to close the openings b.When there is an accumulation of water back of the pistons-21s., betweenthe pistons and the valvesand the former are caused 'tomove back, thevalves will also recede and allow the water to escape through theoutlets b and chutes B. As the pistons make their return or forwardstrokes the springs F will cause the valves to close the outlets b.

By the mechanism shown for operating the pistons it will be seen thatthey receive alternate forward and backward strokes.

Having described my invention, I claim- In a marine propeller consistingof a cylinder, A, an outlet, b, and a chute, B, and a piston, O, thecombination therewith of the cylindrical valve D! and its spring F,substantially in the manner and for the purpose described.

In testimony whereof I affix my signature, in presence of two witnesses,this 23d day of July, 1881.

HUGH MULHOLLEN.

IVitnesses H. H. KLINE, ROBERT WARING.

